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horseshoe shrimp

...of 37 mm (1.5 inches), occurs on the Atlantic coast of the northeastern United States.
Lightiella incisa, about 2.6 mm (0.10 inch) in length, is found in waters near Puerto Rico;
L.serendipita, 3.2 mm (0.13 inch) long, occurs in San Francisco Bay on the coast of California.
Sandersiella acuminata, 2.4 mm (0.094 inch) long, is found in waters near Japan and New...